You Mix Two Bacterial Stains in a Tube of Glucose-Salts

Multiple Choice

You mix two bacterial stains in a tube of glucose-salts agar. One strain is His−, Val−, while the other strain is Trp−, Leu−. You previously showed that neither strain grows on glucose-salts agar. After incubating the tube, you plate a sample onto a new glucose-salts agar plate. Several colonies grow. What do you know is True about these colonies?

A) The bacteria in the colonies are His−, Val−, Trp⁺, Leu⁺.
B) The bacteria in the colonies are His−, Val⁺, Trp⁺, Leu⁺.
C) The bacteria in the colonies are His−, Val−, Trp−, Leu−.
D) The bacteria in the colonies are His⁺, Val⁺, Trp⁺, Leu⁺.
E) The bacteria in the colonies are His⁺, Val⁺, Trp⁺, Leu⁺, Penᴿ.